Randomized controlled trial of the effects of vitamin D–fortified milk and bread on serum 25-hydroxyvitamin D concentrations in families in Denmark during winter: the VitmaD study

Strategic food vehicles for vitamin D fortification and effects on vitamin D status: A systematic review and meta-analysis of randomised controlled trials

There has been growing interest in the potential of vitamin D food fortification in Europe as a means of addressing low vitamin D status. The WHO-FAO suggest that choosing a suitable food vehicle and ensuring the combination of the food vehicle and the fortificant will be efficacious and effective are of key importance to a successful food fortification programme. Our key objective was to conduct a systematic review and meta-analysis to investigate the effect of various animal- and plant-based food vehicles fortified with vitamin D (as D3 or D2) on circulating 25-hydroxyvitamin D [25(OH)D] concentrations. A list of prioritised food vehicles was established and we searched PubMed, Embase, Scopus and Web of Science for randomised controlled trials (RCTs) which used these vehicles individually, and which met prespecified criteria. The searches identified 49 papers which described suitable RCTs using vitamin D-fortified bread/savoury biscuits (n = 5), orange juice (n = 5), UV-mushrooms (n = 8), cheese (n = 3), yogurt (n = 5), fluid milk (n = 13), powdered milk (n = 5), eggs (n = 2), edible oils (n = 4), or breakfast cereal (n = 1). No suitable RCTs were identified for rice, maize flour, butter, margarine or dairy spreads, plant-based milk or yogurt alternatives. Random-effects meta-analyses of each food vehicle individually indicated weighted mean differences (WMD) in 25(OH)D in the range ∼9-35 nmol/L (3-15 RCT arms, depending on vehicle), and all statistically significant (P < 0.01-0.0001), with the exception of UV-mushrooms (P = 0.06). Heterogeneity was variable (I2 =33-99%, depending on vehicle), but subgroup analysis based on vitamer and dose reduced it in some instances. Sub-group analysis on the basis of whether the food vehicles were from plant-based or animal-based origin showed no significant difference in WMD (15.2 versus 15.9 nmol/L, respectively; P = 0.48). These results support the use of various animal- and plant-based food vehicles for vitamin D fortification to improve circulating 25(OH)D concentrations in populations. This work was registered with PROSPERO as CRD42023439883.

Effect of Vitamin D in Long COVID Patients

Vitamin D deficiency has been studied in the context of acute coronavirus disease 2019 (COVID-19), revealing associations with increased severity and mortality. Yet, the influence of vitamin D on long COVID symptoms remains unknown. The purpose of this study is to examine the effect of vitamin D on long COVID symptoms. Over the study period, 50,432 individuals within the catchment area of the outpatient COVID-19 clinic tested positive for SARS-CoV-2 via PCR, with 547 patients subsequently referred to a specialized Post-COVID Clinic, and 447 of them enrolled in the study. Patient-reported symptoms and paraclinical measures including vitamin D were evaluated in 442 patients. The majority of participants were female (72%, n = 320/442). The consumption of alcohol and number of current smokers were low. Low vitamin D was observed in 26% (n = 115/442) of the patients, most commonly in male participants (odds ratio (OR) = 1.77, 95% confidence interval (CI) (1.12, 2.79), p = 0.014). Additionally, low vitamin D was correlated with a younger mean age of 41 years (standard deviation (SD) = 12) as opposed to 48 years (SD = 13) in patients with normal vitamin D levels (OR = 0.96, 95% CI (0.94, 0.97), p < 0.001). While our study population indicated a potentially higher prevalence of vitamin D insufficiency in this population compared to the general population, no significant differences in prevalence of symptom or symptom severity scores were observed between the low and normal vitamin D groups. In patients in a Post-COVID Clinic, we found no association between vitamin D levels and long COVID symptoms.

A Mixed Model Approach for Estimating the Optimal Food Fortification of Vitamin D: Experiment Based on Mashhad Cohort Study in Iran

BACKGROUND

Vitamin D deficiency is a prevalent problem in worldwide healthcare related to several system disorders. Food fortification as a solution is associated with several challenges including insufficient coverage of the entire population, required degree of fortification, the vehicles used for fortification and potential toxicity. This study aimed to determine the optimal amount of vitamin D for fortification without surpassing the upper intake level (UL) of intake at the 95th percentile of the Iranian population and compare two methods of food fortification.

METHODS

This study is aimed to develop a model of two different fortifying approaches related to an available dataset called MASHAD cohort study. The dataset comprised demographic and nutritional data of 9704 Iranian individuals living in the Greater Mashhad region. The first approach was a computational method necessary to implement a range of eight foods and calculate the optimal approach. In the second case, we used the European formula method called ILSI.

RESULTS

To find the appropriate value for fortification, we calculated the consumption of 400 IU and 1000 IU supplements of vitamin D. Three micrograms per 100 g in each food was the optimal output. We also used Flynn and Rasmussen's formula on our data. Using these methods, we found that 2.1 micrograms per 100 kcal provides the best result. Hence, using the two different approaches, the results appear to be consistent and promising.

CONCLUSION

One interesting finding was that supplement consumption did not greatly affect the impact of fortification. This observation may support the hypothesis to determine the amount of fortification, and we can ignore the study population's supplement consumption.

Fortification of Staple Foods for Household Use with Vitamin D: An Overview of Systematic Reviews

Vitamin D deficiency is a global public health concern with significant implications for bone health and chronic disease prevention. Our aim was to summarize the evidence from Cochrane and other systematic reviews evaluating the benefits or harms of vitamin D fortification of staple foods for household use. In April 2023, we systematically searched Ovid MEDLINE, Embase, Epistemonikos and the Cochrane Database of Systematic Reviews for systematic reviews investigating the effects of vitamin D fortification of food in general populations of any age. We used Cochrane methodology and assessed the methodological quality of included studies using AMSTAR (A MeaSurement Tool to Assess Systematic Reviews). We assessed the degree of overlap among reviews. All outcomes included in systematic reviews were assessed. The protocol is registered in PROSPERO (registration number: CRD42023420991). We included 27 systematic reviews out of 5028 records for analysis. Overall, 11 out of 12 systematic reviews calculating pooled estimates reported a significant increase in serum 25(OH)D concentrations. The mean change in serum 25(OH)D concentrations per additional 100 units of vitamin D ranged from 0.7 to 10.8 nmol/L. Fortification of food with vitamin D showed a reduction in the prevalence of vitamin D deficiency based on high-certainty evidence. Parathormone (PTH) levels were described to decrease, bone mineral density to increase, while the effects on other bone turnover markers were inconsistent. Fortification did not significantly impact most anthropometric parameters, but it seemed to positively influence lipid profiles. In summary, fortification of food with vitamin D results in a reduction of vitamin D deficiency and might increase serum 25(OH)D concentrations, to varying extents depending on the fortified vehicle and population characteristics. Additionally, fortification may have a positive impact on bone turnover and lipid metabolism but may only have a limited effect on anthropometric parameters.

Influence of food matrix delivery system on the bioavailability of vitamin D3: A randomized crossover trial in postmenopausal women

OBJECTIVES

Vitamin D insufficiency (blood 25-hydroxyvitamin D <50 nmol/L) is a global health problem. Vitamin D food fortification might be a solution, but knowledge is sparse on which food matrices yield the highest bioavailability. The aim of this study was to investigate the influence of different food matrices including complex formations with whey proteins on the human bioavailability of vitamin D.

METHODS

In this randomized, multiple crossover trial, we enrolled 30 postmenopausal women 60 to 80 y of age with vitamin D insufficiency. We measured changes in serum concentrations of vitamin D₃ (D₃) postprandially for 24 h in response to the intake of 500 mL of different food matrices with 200 µg D₃ added compared with a control (500 mL of water). Foods included apple juice with whey protein isolate (WPI), apple juice, semi-skim milk, and water (with D₃). The food matrices were provided in a randomized order with ≥10-d washout period between them. On each intervention day, blood samples were collected at 0, 2, 4, 6, 8, 10, 12 and 24 h.

RESULTS

D₃ with WPI in juice did not enhance area under the curve (AUC) of serum D₃ compared with juice without WPI (370 nmol ×  24 h/L; 95% confidence interval [CI], 321-419 versus 357 nmol ×  24 h/L; 95% CI, 308-406 nmol ×  24 h/L; P = 0.65). However, compared with juice, the AUC was significantly higher in response to the intake of D₃ in milk (452 nmol ×  24 h/L; 95% CI, 402-502 nmol ×  24 h/L) and water with D₃ (479 nmol ×  24 h/L; 95% CI, 430-527 nmol ×  24 h/L; P < 0.05). No difference was observed between milk and water (P = 0.34).

CONCLUSIONS

The bioavailability of D₃ was superior in milk and water compared with juice, regardless of whether WPI was added.

A Data Driven Approach to Identify Safe and Adequate Schemes for Vitamin D Fortification

Food fortification is a strategy to increase low vitamin D intake. In order to avoid the intake of a population exceeding the upper tolerable intake level, the right choice of food groups to fortify is of crucial importance. An automated fortification tool was developed based on dietary intake data from the Danish National Survey of Dietary Habits and Physical Activity 2011-2013 (DANSDA), taking into account the energy contribution of the fortified food. The fortification of food group is a variant in the linear modelling, where the optimization ensures the lowest possible variation in deviation of the calculated intake and the target intake. The resulting tool demonstrated that the lowest limit of fortification, where the model works, is 12 µg/10 MJ, when fortification of any food group is allowed. The tool also demonstrated that, by increasing the allowed upper level of fortification from 12 µg/10 MJ up to 30 µg/10 MJ, the food groups selected for fortification and the level of fortification in those food groups may change. Specifically, fewer food groups seem to be needed as the upper level of fortification is increased. The optimized scenarios, using the food groups, including milk, cheese, cereals, fats, and juice, were tested on dietary-survey data and demonstrated that all the projected scenarios manage to lift the median vitamin D intake to the targeted intake safely. A data-driven approach was used to develop a simple, fast, and automated fortification tool to test different vitamin D food fortification strategies.

Vitamin D intake and bone mineral density in Korean adults: analysis of the 2009-2011 Korea National Health and Nutrition Examination Survey

BACKGROUND/OBJECTIVES

The prevalence of vitamin D deficiency in Koreans is quite high; however, until recently, Korean National Health and Nutrition Survey (KNHANES) had not analyzed the vitamin D intake among Koreans. Additionally, the Korean Dietary Reference Intake for vitamin D was established based on insufficient evidence. Therefore, we investigated vitamin D intake and its relationship with bone mineral density (BMD) in Korean adults using the combined data from the 2009-2011 KNHANES.

MATERIALS AND METHODS

This study was conducted in 11,949 healthy adults. Vitamin D intake was assessed using a 24-h recall method, and the BMD was measured using dual-energy X-ray absorptiometry.

RESULTS

The prevalence of vitamin D deficiency (< 20 ng/mL) was 64% in men and 77% in women. In women aged ≥ 50 yrs and men aged < 50 yrs, there was a significant positive correlation between vitamin D intake and serum 25-hydroxyvitamin D level after sun exposure adjustment. The BMD of postmenopausal women aged ≥ 50 yrs with a vitamin D intake of 5 µg/day or more was significantly higher than that of women with intake less than 5 µg/day. After adjusting for age, energy, and calcium intake, the vitamin D intake of the osteoporotic group was significantly lower than that of the osteopenia group in women.

CONCLUSIONS

Since the relationship between vitamin D intake and BMD was observed in women aged ≥ 50 yrs, further research is needed to clarify these findings using cohort or randomized controlled trials.

Vitamin D Deficiency in Farm Animals: A Review

One of the most effective vitamins in the musculoskeletal structure and immune system of farm animals is Vitamin D. The widespread risk of Vitamin D deficiency states is known widely resulting in autoimmune diseases, diabetes, rickets, metabolic bone diseases, and cancers. The aim of this review is to address the subject of Vitamin D deficiency in farm animals and the role of vitamin D in health and deficiency states. Although Vitamin D deficiency is generally defined as < 20 ng/mL in serum, but this level remains to be discussed. Vitamin D synthesis in the skin is the major source of Vitamin D in the body and is influenced by genetic and several environmental factors, such as length of sun exposure, season, and latitude. Sun exposure might be limited during winter in some areas, such as northern latitudes. Thus, food sources can play essential roles in supplying the demand for vitamin D. Some animal species have more sensitivity to Vitamin D deficiency due to their different metabolism, homeostasis, and adaptation to specific diets and environments. Farm animal species, such as cattle, pigs, llamas, Alpacas, small ruminants, and broiler chickens are more sensitive to Vitamin D deficiency. However, some farm animal species including horses and donkeys usually have a low risk of Vitamin D deficiency. Therefore, the management of Vitamin D deficiency and its consequences are critical in some species. The inclusion of Vitamin D in the body of farm animals depended on farming practices, sun exposure in different seasons, and the content of diets. Due to the diversity of species, regulation of many ongoing processes in animals’ bodies, the complexity of Vitamin D metabolism, and different metabolites, more studies are necessary to find the vital roles of vitamin D in the prevention and control of diseases in farm animals.

Different Vitamin D Supplementation Strategies in the First Years of Life: A Systematic Review

Vitamin D (VD) is an essential micronutrient with multiple functions for human growth, and adequate intake should be guaranteed throughout life. However, VD insufficiency is observed in infants all over the world. Low VD concentration in the breast milk of non-supplemented mothers and low compliance to VD daily supplementation are the main causes of VD insufficiency, especially in the long term. Furthermore, VD supplementation dosages are still debated and differ by country. We conducted a systematic review to compare the most recent evidence on different postnatal VD supplementation strategies, determining whether supplementation given to the mother is as effective as that administered directly to the child, and whether different dosages and administration schedules differ significantly in terms of efficacy and safety. We identified 18 randomized controlled trials (RCTs) addressing the role of infant (n = 961), maternal (n = 652) or combined infant and maternal VD supplementation (n = 260 pairs). In all studies, similar outcomes emerged in terms of efficacy and safety. According to our findings, alternative approaches of VD supplementation may be adopted, especially in cases where the adherence to daily supplementation strategies is poor. This review shows that different dosages and supplementation strategies result in similar VD sufficiency rates. Therefore, international guidelines may be revised in the future to offer multiple and different options of supplementation for specific settings and ages.

Reasonableness of Enriching Cow’s Milk with Vitamins and Minerals

Milk is an exceptional nutritional product that has been used for many millennia in human nutrition. Milk is a source of many valuable nutrients, including calcium, vitamin B, an especially significant amount of vitamin B2 and fat-soluble vitamins, such as A, D and E. Milk is an attractive product for fortification as it has a high nutritional density in a small volume and a relatively low price. Research shows positive health effects of drinking milk and consuming dairy products. Even more health benefits can be obtained from consuming fortified dairy products. A literature review, current nutritional recommendations, medical recommendations and an analysis of the market situation all recommend introducing milk enriched with minerals in combination with vitamins to the market. This concept corresponds to the current market demand and may supplement the missing and expected range of fortified milk and the correct number of recipients.

Vitamin d-fortified bread: Systematic review of fortification approaches and clinical studies

Vitamin d-fortified bread has been proposed as a strategy to increase the average daily intake and serum status of this nutrient. This review aimed to bring together the different types of scientific articles on vitamin d-fortified bread. The databases used for the research were PUBMED, WEB of SCIENCE and SCOPUS; all original indexed studies written in English, published between January 2000 and March 2021, were considered. Three important points were identified: i) theoretical models of fortification; ii) stability, bioaccessibility, and bioavailability studies of vitamin d-fortified breads; and iii) clinical effects of vitamin d-fortified breads. This review showed that vitamin d-fortified bread is a promising vehicle for fortification strategy effects, leading to increased serum concentrations of 25(OH)D and decreased parathyroid hormone. However, further studies are needed to elucidate the effects and effectiveness of this fortification strategy in the prevention/treatment of vitamin D deficiency.

Vitamin D Status and Health Outcomes in School Children in Northern Ireland: Year One Results from the D-VinCHI Study

(1) Background: Vitamin D status has never been investigated in children in Northern Ireland (UK). (2) Methods: Children (4-11 years) (n = 47) were recruited from November 2019 to March 2020 onto the cross-sectional study. Anthropometry was assessed. Plasma 25-hydroxyvitamin D (25(OH)D) was analysed. Vitamin D intake, parental knowledge and perceptions, participant habits, physical activity and sedentary behaviour were established via questionnaire. Muscle strength was assessed via isometric grip strength dynamometry and balance via dominant single-leg and tandem stance. Parathyroid hormone, bone turnover markers (OC, CTX and P1NP), glycated haemoglobin and inflammatory markers (CRP, IFN-γ, IL-10, IL-12p70, IL-13, IL-1β, IL-2, IL-4, IL-6, IL-8 and TNF-α) were analysed. (3) Results: Mean (SD) 25(OH)D was 49.17 (17.04) nmol/L (n = 47); 44.7% of the children were vitamin D sufficient (25(OH)D >50 nmol/L), 48.9% were insufficient (25-50 nmol/L) and 6.4% were deficient (<25 nmol/L). 25(OH)D was positively correlated with vitamin D intake (µg/day) (p = 0.012, r = 0.374), spring/summer outdoor hours (p = 0.006, r = 0.402) and dominant grip strength (kg) (p = 0.044, r = 0.317). Vitamin D sufficient participants had higher dietary vitamin D intake (µg/day) (p = 0.021), supplement intake (µg/day) (p = 0.028) and spring/summer outdoor hours (p = 0.015). (4) Conclusion: Over half of the children were vitamin D deficient or insufficient. Wintertime supplementation, the consumption of vitamin D rich foods and spring/summer outdoor activities should be encouraged to minimise the risk of vitamin D inadequacy.

Potential of Vitamin D Food Fortification in Prevention of Cancer Deaths-A Modeling Study

Meta-analyses of randomized controlled trials (RCTs) have estimated a 13% reduction of cancer mortality by vitamin D supplementation among older adults. We evaluated if and to what extent similar effects might be expected from vitamin D fortification of foods. We reviewed the literature on RCTs assessing the impact of vitamin D supplementation on cancer mortality, on increases of vitamin D levels by either supplementation or food fortification, and on costs of supplementation or fortification. Then, we derived expected effects on total cancer mortality and related costs and savings from potential implementation of vitamin D food fortification in Germany and compared the results to those for supplementation. In RCTs with vitamin D supplementation in average doses of 820-2000 IU per day, serum concentrations of 25-hydroxy-vitamin D increased by 15-30 nmol/L, respectively. Studies on food fortification found increases by 10-42 nmol/L, thus largely in the range of increases previously demonstrated by supplementation. Fortification is estimated to be considerably less expensive than supplementation. It might be similarly effective as supplementation in reducing cancer mortality and might even achieve such reduction at substantially larger net savings. Although vitamin D overdoses are unlikely in food fortification programs, implementation should be accompanied by a study monitoring the frequency of potentially occurring adverse effects by overdoses, such as hypercalcemia. Future studies on effectiveness of vitamin D supplementation and fortification are warranted.

Inadequate vitamin D intake among pregnant women in Malaysia based on revised recommended nutrient intakes value and potential dietary strategies to tackle the inadequacy

BACKGROUND/OBJECTIVES

Recently, the recommended nutrient intakes (RNI) for vitamin D for Malaysian aged 1-70 yrs has been revised from 5 µg/day to 15 µg/day. This study is aimed to assess the adequacy of vitamin D intake based on revised RNI and to recommend several dietary strategies to increase total vitamin D intake.

SUBJECTS/METHODS

Vitamin D intake from both food and supplement of 217 pregnant women was assessed using a validated food frequency questionnaire. Hypothetical effect of expanded supplementation and food fortifications strategies were modelled using the consumption data.

RESULTS

The results revealed that more than half (67.7%) of pregnant women had inadequate vitamin D intake (RNI < 15 µg/day). The modelling results demonstrated the potential of universal provision of 10 µg/day of multivitamins supplements in increasing vitamin D intake. Moreover, mandatory fortification of both milk and malted drink at single level of 5 µg/serving would lead to increase in vitamin D intake of Malaysians, particularly pregnant women.

CONCLUSIONS

The outcome of this study can be used as a reference for public health professionals to re-evaluate the existing Malaysian food fortification policies and supplementation recommendation for vitamin D for pregnant women.

Health implication of vitamin D on the cardiovascular and the renal system

Vitamin D regulates the calcium and phosphorus balance in the body. The activated form of vitamin D (1 α,25-dihydroxyvitamin D) binds to vitamin D receptor which regulates genes that control cell proliferation, differentiation and apoptosis. In the cardiovascular system, the vitamin D receptor is present in cardiomyocytes and the arterial wall. A clear correlation between vitamin D level and cardiovascular diseases is established. Vitamin D deficiency affects the renin-angiotensin system leading to ventricular hypertrophy and eventually to stroke. While clinical trials highlighted the positive effects of vitamin D supplements on cardiovascular disease these still need to be confirmed. This review outlines the association between vitamin D and cardiovascular and renal disease summarising the experimental data of selective cardiovascular disorders.

Prenatal and Early Life Exposure to the Danish Mandatory Vitamin D Fortification Policy Might Prevent Inflammatory Bowel Disease Later in Life: A Societal Experiment

This register-based national cohort study of 206,900 individuals investigated whether prenatal exposure to small extra doses of vitamin D from fortified margarine prevented inflammatory bowel disease (IBD) later in life; whether the risk of IBD varied according to month or season of birth; and finally, whether there was an interaction between exposure to extra D vitamin and month or season of birth. Fortification of margarine with vitamin D was mandatory in Denmark from the mid-1930s until 1st June 1985, when it was abolished. Two entire birth cohorts, each including two years, were defined: one exposed and one unexposed to the fortification policy for the entire gestation. All individuals were followed for 30 years from the day of birth for an IBD diagnosis in Danish hospital registers. Logistic regression analyses were used to estimate odds ratios (OR) and 95% confidence intervals (CI). Odds for IBD was lower among those exposed to extra D vitamin compared to those unexposed, OR = 0.87 (95% CI: 0.79; 0.95). No association with month or season of birth was found. However, estimates suggested that particularly children born during autumn may have benefitted from the effect of small extra doses of vitamin D. This is, to our knowledge, the first study to explore if prenatal exposure to vitamin D from fortification influenced the risk of IBD. Our results suggest that prenatal exposure to small amounts of extra vitamin D from food fortification may protect against the development of IBD before 30 years of age.

Approaches to setting dietary reference values for micronutrients, and translation into recommendations

Dietary reference values (DRV) are estimates of the daily amounts of nutrients or food energy that meet the needs of healthy people. In the UK, three terms are used to express these estimates, assuming a normal distribution of requirements in a population. These are the estimated average requirement, the lower reference nutrient intake and the reference nutrient intake. DRV are for use in a variety of settings, including the assessment of adequacy and safety of nutrient or energy intake in a population group, in the design of meal provision in care settings, in food labelling and in considering food fortification strategies. DRV, and other expressions of nutrient requirements, assume a relationship between the intake of a nutrient and some criterion of adequacy, the outcome. Estimates of requirements are based on a diverse range of measures of adequacy, according to available evidence. The Scientific Advisory Committee on Nutrition (SACN) is the body responsible for reviewing and setting DRV for the UK population. The work of SACN is guided by a framework of evidence that relates food and nutrients to health. There have been calls for the harmonisation of approaches used in the setting of nutrient requirements, globally, and an increased transparency in the decision-making process. Some progress has been made in this regard, but there is a great deal of work to be done.

Adequate Vitamin D Intake Cannot Be Achieved within Carbon Emission Limits Unless Food Is Fortified: A Simulation Study

This study applied linear programming using a Dutch "model diet" to simulate the dietary shifts needed in order to optimize the intake of vitamin D and to minimize the carbon footprint, considering the popularity of the diet. Scenarios were modelled without and with additional fortified bread, milk, and oil as options in the diets. The baseline diet provided about one fifth of the adequate intake of vitamin D from natural food sources and voluntary vitamin D-fortified foods. Nevertheless, when optimizing this diet for vitamin D, these food sources together were insufficient to meet the adequate intake required, unless the carbon emission and calorie intake were increased almost 3-fold and 2-fold, respectively. When vitamin D-fortified bread, milk, and oil were added as options to the diet, along with increases in fish consumption, and decreases in sugar, snack, and cake consumption, adequate intakes for vitamin D and other nutrients could be met within the 2000 kcal limits, along with a relatively unchanged carbon footprint. Achieving vitamin D goals while reducing the carbon footprint by 10% was only possible when compromising on the popularity of the diet. Adding vitamin D to foods did not contribute to the total carbon emissions. The modelling study shows that it is impossible to obtain adequate vitamin D through realistic dietary shifts alone, unless more vitamin D-fortified foods are a necessary part of the diet.

Ten2Twenty-Ghana: Study Design and Methods for an Innovative Randomized Controlled Trial with Multiple-Micronutrient-Fortified Biscuits among Adolescent Girls in Northeastern Ghana

Investing in adolescent girls' nutrition is vital for health and for breaking the intergenerational cycle of malnutrition and deprivation, but limited knowledge on the type, timing, and efficacy of interventions delays progress. We describe the design of a 26-wk randomized placebo-controlled trial with multiple-micronutrient-fortified biscuits (MMBs) among adolescent girls in northeastern Ghana. Apparently healthy, premenarche (n = 312) and postmenarche (n = 309) girls (10-17 y) were randomly assigned to receive the following for 5 d/wk: 1) MMBs (fortified with 11 vitamins and 7 minerals) or 2) unfortified biscuits. Data included plasma micronutrient status, anthropometry, body composition, cognitive function, psychosocial health, fertility, dietary intake, and sociodemographic and socioeconomic covariates, complemented with in-depth interviews (n = 30) and 4 focus group discussions. We hypothesized an increase in plasma ferritin and retinol-binding protein with a resultant increase in hemoglobin, cognition, vertical height, and psychosocial health. Our study seeks to investigate the efficacy and optimal timing of a multiple-micronutrient food intervention program for adolescent girls. The RCT was registered prospectively with the Netherlands Clinical Trials Register (NL7487).

Vitamin D deficiency 2.0: an update on the current status worldwide

Vitamin D testing and the use of vitamin D supplements have increased substantially in recent years. Currently, the role of vitamin D supplementation, and the optimal vitamin D dose and status, is a subject of debate, because large interventional studies have been unable to show a clear benefit (in mostly vitamin D replete populations). This may be attributed to limitations in trial design, as most studies did not meet the basic requirements of a nutrient intervention study, including vitamin D-replete populations, too small sample sizes, and inconsistent intervention methods regarding dose and metabolites. Vitamin D deficiency (serum 25-hydroxyvitamin D [25(OH)D] < 50 nmol/L or 20 ng/ml) is associated with unfavorable skeletal outcomes, including fractures and bone loss. A 25(OH)D level of >50 nmol/L or 20 ng/ml is, therefore, the primary treatment goal, although some data suggest a benefit for a higher threshold. Severe vitamin D deficiency with a 25(OH)D concentration below <30 nmol/L (or 12 ng/ml) dramatically increases the risk of excess mortality, infections, and many other diseases, and should be avoided whenever possible. The data on a benefit for mortality and prevention of infections, at least in severely deficient individuals, appear convincing. Vitamin D is clearly not a panacea, and is most likely efficient only in deficiency. Given its rare side effects and its relatively wide safety margin, it may be an important, inexpensive, and safe adjuvant therapy for many diseases, but future large and well-designed studies should evaluate this further. A worldwide public health intervention that includes vitamin D supplementation in certain risk groups, and systematic vitamin D food fortification to avoid severe vitamin D deficiency, would appear to be important. In this narrative review, the current international literature on vitamin D deficiency, its relevance, and therapeutic options is discussed.

The impact of vitamin D food fortification and health outcomes in children: a systematic review and meta-regression

OBJECTIVE

Vitamin D (vitD) deficiency is a global childhood health problem. Food fortification is a promising strategy to curb vitD deficiency. We aimed to assess the effectiveness of utilizing vitD fortification in staple foods to improve 25hydroxyvitamin D (25(OH)D) concentration and to reduce the prevalence of vitD deficiency among healthy children.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating the use of vitD fortified food products compared to no fortification among healthy children aged 1-18 years old. We searched Medline, Embase, Global Health, and Cochrane (CENTRAL) databases from database inception until May 2019. Independently, six reviewers in pairs screened titles and abstracts, assessed the full text for eligibility, and performed data extraction and quality assessment. The primary outcome is the impact of fortification on 25(OH)D concentration. The secondary outcomes included the impact of fortification on the prevalence of vitD deficiency, school performance, cognitive function, school absences, infection rate, hospital admission length, and compliance with fortified food product consumption.

RESULTS

We identified 2229 articles. After assessing eligibility, 20 RCTs met the inclusion criteria. The eligible RCTs assessed the fortification of milk, cereal, juice, bread, yogurt, and cheese compared with no fortification. All RCTs, except for three, had a low risk of bias. Food fortification improved 25(OH)D concentration by a mean difference (MD) of 15.51 nmol/L (95% confidence interval (CI) 6.28, 24.74; I² = 99%), which resulted in a mean increase of 3 nmol/l for every 100 IU of vitD, when adjusted for baseline 25(OH)D concentration and country latitude. Additionally, the prevalence of vitD deficiency decreased by a risk ratio of 0.53 (95% CI 0.41, 0.69; I² = 95%), and cognitive function improved by a MD of 1.22 intelligence quotient (IQ) points (95% CI 0.65, 1.79; I² = 0%). The overall evidence quality was high.

CONCLUSION

VitD food fortification is an effective way to improve 25(OH)D concentration, prevent vitD deficiency, and improve IQ levels.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017057631.

Food-based strategies for prevention of vitamin D deficiency as informed by vitamin D dietary guidelines, and consideration of minimal-risk UVB radiation exposure in future guidelines

There is widespread acknowledgement of the presence of vitamin D deficiency in the community and the pressing need to address this. From a public health perspective, emphasis has been placed on addressing vitamin D deficiency through dietary means. However, naturally rich food sources of vitamin D are few and infrequently consumed, and nutrition survey data from various countries have indicated that habitual vitamin D intakes in the community are much lower than the current vitamin D dietary guidelines. This review will briefly overview the extent of vitamin D deficiency within the community, its causes, and how our food chain, once its embraces the evidence-based practise of food fortification and potentially biofortification, can cater for meeting the dietary vitamin D needs of the community. Finally, international authorities, briefed with establishing vitamin D dietary guidelines over the past decade, have struggled with uncertainties and gaps in our understanding of the relative contribution of sunshine and diet to vitamin D status and vitamin D requirements for health maintenance. The review will also consider how emerging evidence of a possible minimal-risk UVB radiation exposure relative to skin cancer that also enables vitamin D production could greatly inform future vitamin D dietary guidelines.

Efficacy and safety of food fortification to improve vitamin D intakes of older adults

OBJECTIVES

The aim of this study was to determine the best foods for potential vitamin D food fortification and to model the efficacy and safety of different food fortification scenarios in adults ≥50 y of age in Ireland.

METHODS

National Adult Nutrition Survey vitamin D data for participants ≥50 y of age were updated. Vitamin D from foods with natural and added vitamin D was estimated and daily vitamin D intake patterns were examined. Data modeling was used to estimate the effects of target food fortification scenarios.

RESULTS

Almost two-thirds of the mean daily vitamin D intake of adults ≥50 y of age (7 ± 7 µg) comes from foods with added vitamin D. Milk and bread are the most frequently consumed foods across all meals and were subsequently targeted for the data modeling exercise. Results from the data modeling show that vitamin D intake increased between 9 and 17 µg/d, depending on the fortification scenario. Fortifying milk or bread resulted in ∼30% or ∼55% of individuals meeting the Recommended Daily Allowance (RDA); however, fortifying both simultaneously resulted in ∼70% meeting the RDA.

CONCLUSIONS

Currently, the majority of Irish adults ≥50 y of age are not meeting dietary recommendations for vitamin D. Fortification of commonly consumed foods such as milk and bread could improve daily intakes such that ∼70% of the cohort would meet the minimum recommendation. Future research should examine the efficacy of different food fortification scenarios to improve vitamin D intakes for older adults.

Vitamin D Deficiency: Defining, Prevalence, Causes, and Strategies of Addressing

There are variable definitions of vitamin D deficiency, based on different thresholds of serum 25-hydroxyvitamin D (25(OH)D); this has a major bearing on the prevalence estimates of vitamin D deficiency and consequently on the magnitude of the public health issue of low vitamin D status. Despite this, there is widespread acknowledgement of the presence of vitamin D deficiency, even using the most conservative serum 25(OH)D threshold of < 25/30 nmol/L, in both low- and high-income country setting and the pressing need to address this deficiency. While ultraviolet B-rich sunlight stimulates synthesis of vitamin D in skin, there are environmental factors and personal characteristics which prevent or impede such dermal synthesis. There are several complexities and concerns in advocating sun exposure as a public health approach for increasing vitamin D status. This places increased emphasis on addressing vitamin D deficiency through dietary means. However, naturally rich sources of vitamin D are few and infrequently consumed, and nutrition surveillance data from various countries have indicated that habitual vitamin D intakes in the population are much lower than the recommendations. There are a number of strategies that can be considered for the control of micronutrient malnutrition, these include (i) increasing the diversity of foods consumed, (ii) food fortification, and (iii) supplementation. The present narrative review will consider these strategies for addressing low dietary vitamin D intake and consequently lowering the risk of vitamin D deficiency.

Effect of vitamin D fortified foods on bone markers and muscle strength in women of Pakistani and Danish origin living in Denmark: a randomised controlled trial

BACKGROUND

Deficient and insufficient vitamin D status (defined as serum 25(OH)D < 30 nmol/L and > 50 nmol/L) is prevalent worldwide and associated with decreased muscle strength and poor bone health. We aimed to investigate the effect of vitamin D fortification on bone markers and muscle strength among younger adult women at risk of vitamin D deficiency.

METHODS

A 12-week randomised double-blinded placebo-controlled winter intervention trial, providing 30 μg vitamin D₃/day through fortified yoghurt, cheese, eggs and crisp-bread or similar placebo products. Participants were 143 women of Danish and Pakistani origin 18-50 years of age, living in Denmark, randomised into four groups stratified by ethnicity. Serum 25-hydroxyvitamin D (25(OH)D) by LC-MS/MS and the secondary endpoints: four specific bone markers (osteocalcin (OC), Bone specific Alkaline Phosphatase (BALP), Procollagen type 1 amino-terminal propeptide (P1NP), C-terminal crosslinked telopeptide of type 1 collagen (CTX)) and three muscle strength measures (handgrip, knee extension strength, chair-standing), were assessed using one-way ANOVA, Tukey HSD and subsequent linear ANCOVA models, adjusted for relevant covariates.

RESULTS

Significantly increased serum 25(OH)D concentration from 53.3 (17) to 77.8 (14) nmol/L and from 44.5 (21) to 54.7 (18) nmol/L among Danish and Pakistani women in the fortified groups, respectively (P <  0.05). The bone turnover markers OC, BALP, P1NP and CTX did not change significantly. Muscle strength by handgrip, knee extension and chair-standing test did not change significantly following the intervention.

CONCLUSIONS

Consumption of vitamin D fortified foods for 12 weeks did not result in significant changes of the bone turnover markers OC, BALP, P1NP and CTX. Muscle strength measured as hand grip strength, knee extension strength and chair-standing did not change significantly following the intervention.

Chances of live birth after exposure to vitamin D-fortified margarine in women with fertility problems: results from a Danish population-based cohort study

OBJECTIVE

To study the association between extra vitamin D from a mandatory margarine fortification program and chance of live birth among infertile women.

DESIGN

Nationwide cohort study.

SETTING

Not applicable.

PATIENT(S)

The study population consisted of 16,212 women diagnosed with infertility from June 1, 1980, to August 31, 1991.

INTERVENTIONS(S)

We took advantage of the mandatory vitamin D fortification program of margarine in Denmark that was abruptly stopped on May 31, 1985. The termination of the vitamin D fortification served as a cutoff point to separate the study population into various exposure groups.

MAIN OUTCOME MEASURE(S)

Odds ratios and 95% confidence intervals for the association between vitamin D exposure status and chance of a live birth within 12, 15, and 18 months after first infertility diagnosis.

RESULT(S)

Women who were diagnosed with infertility during the vitamin D-exposed period had an increased chance of a live birth compared with women diagnosed with infertility during the nonexposed period. For women diagnosed with infertility during the wash-out period, the chance of a live birth was also increased, but somewhat lower. Similar estimates were obtained with longer follow-up, in women with anovulatory infertility, and little seasonal variation was observed when calendar period of conception was applied.

CONCLUSION(S)

Our findings suggest that infertile women exposed to extra vitamin D from a margarine fortification program had an increased chance of live birth compared with women not exposed to extra vitamin D from fortification.

Dietary Whole Egg Reduces Body Weight Gain in a Dose-Dependent Manner in Zucker Diabetic Fatty Rats

BACKGROUND

We previously reported that a whole-egg-based diet attenuated weight gain in rats with type 2 diabetes (T2D) and more effectively maintained vitamin D status than an equivalent amount of supplemental cholecalciferol.

OBJECTIVES

The objective of this study was to determine the lowest dose of whole egg effective at maintaining vitamin D homeostasis and attenuating the obese phenotype in T2D rats.

METHODS

Zucker diabetic fatty (ZDF) rats (n = 40; age 6 wk; prediabetic) and their lean controls (n = 40; age 6 wk) were randomly assigned to a diet containing 20% casein (CAS) or 20%, 10%, 5%, or 2.5% protein from whole egg (20% EGG, 10% EGG, 5% EGG, and 2.5% EGG, respectively). All diets contained 20% total protein (wt:wt). All rats received their respective diets for 8 wk, at a stage of growth and development that translates to adolescence in humans, until 14 wk of age, a point at which ZDF rats exhibit overt T2D. Weight gain was measured 5 d/wk, and circulating 25-hydroxyvitamin D [25(OH)D] was measured by ELISA. Mean values were compared by 2-factor ANOVA.

RESULTS

The 20% EGG diet maintained serum 25(OH)D at 30 nmol/L in ZDF rats, whereas the 10%, 5%, and 2.5% EGG diets did not prevent insufficiency, resulting in mean serum 25(OH)D concentrations of 24 nmol/L in ZDF rats. Body weight gain was reduced by 29% (P < 0.001) and 31% (P < 0.001) in ZDF rats consuming 20% and 10% EGG diets, respectively, and by 16% (P = 0.004) and 12% (P = 0.030) in ZDF rats consuming 5% and 2.5% EGG diets, respectively, compared with CAS.

CONCLUSIONS

Whole-egg-based diets exerted a dose-dependent response with respect to attenuating weight gain. These data could support dietary recommendations aimed at body weight management in individuals predisposed to obesity and T2D.

A Novel Approach to Optimize Vitamin D Intake in Belgium through Fortification Based on Representative Food Consumption Data

BACKGROUND

Food fortification is a promising means to improve vitamin D intake of a population. Careful selection of food vehicles is needed to ensure that nearly all individuals within the population benefit from the fortification program.

OBJECTIVES

The aim of the study was to develop and apply a model that simultaneously selects the optimal combination of food vehicles and defines the optimal fortification level that adequately increases vitamin D intake in the population without compromising safety.

METHODS

Food consumption data from the Belgian Food Consumption Survey 2014 (n = 3200; age 3-64 y) were used. The optimization model included 63 combinations of 6 potential vehicles for food fortification, namely "bread," "breakfast cereals," "fats and oils," "fruit juices," "milk and milk beverages," and "yogurt and cream cheese." The optimization procedure was designed to minimize inadequate or excessive vitamin D intake in each of the food combinations. This allowed the relative ranking of the different combinations according to their fortification utility. The estimated average requirement and upper intake level were used as thresholds. An age-specific and population-based approach enabled the sensitivity of the population subgroups to adverse health effects to be taken into account. Feasibility, technical aspects, and healthiness of the food vehicles were used to select the optimal combination.

RESULTS

Multiple combinations of food vehicles significantly reduced the prevalence of inadequate vitamin D intake within the Belgian population (from 92-96% to <2%). Taking other aforementioned criteria into account, the fortification of "milk and milk beverages" and "bread" with 6.9 μg vitamin D/100 kcal was proposed as an optimal fortification scenario.

CONCLUSIONS

The optimization model allows identification of an effective fortification scenario to improve vitamin D intake within the Belgian population based on acceptable risks of inadequate and excessive intake. The model can be extended to other micronutrients and other populations.

Salt Reduction Intervention in Families Investigating Metabolic, Behavioral and Health Effects of Targeted Intake Reductions: Study Protocol for a Four Months Three-Armed, Randomized, Controlled "Real-Life" Trial

Reductions in salt intake have the potential to markedly improve population health at low cost. Real life interventions that explore the feasibility and health effects of a gradual salt reduction lasting at least four weeks are required. The randomized controlled SalT Reduction InterVEntion (STRIVE) trial was developed to investigate the metabolic, behavioral and health effects of four months of consuming gradually salt reduced bread alone or in combination with dietary counselling. This paper describes the rationale and methods of STRIVE. Aiming at 120 healthy families, participants were recruited in February 2018 from the Danish Capital Region and randomly allocated into: (A) Salt reduced bread; (B) Salt reduced bread and dietary counseling; (C) Standard bread. Participants were examined before the intervention and at four months follow-up. Primary outcome is change in salt intake measured by 24 h urine. Secondary outcomes are change in urine measures of potassium and sodium/ potassium ratio, blood pressure, plasma lipids, the renin-angiotensin system, the sympathetic nervous response, dietary intake as well as salt taste sensitivity and preferences. The results will qualify mechanisms affected during a gradual reduction in salt intake in compliance with the current public health recommendations.

Summary Outcomes of the ODIN Project on Food Fortification for Vitamin D Deficiency Prevention

Food-based solutions for optimal vitamin D nutrition and health through the life cycle (ODIN) was a cross-disciplinary, collaborative project, including 30 partners from 19 countries, which aimed to develop evidence-based solutions to prevent low vitamin D status (25-hydroxyvitamin D (25(OH)D) < 30 nmol/L) using a food-first approach. This paper provides a summary overview of some of the important ODIN outcomes and outlines some outstanding data requirements. In a study of almost 56,000 individuals, the first internationally standardised dataset of vitamin D status showed that 13% of EU residents overall, across a latitude gradient of 35° N to 69° N, had serum 25(OH)D < 30 nmol/L and 40% were < 50 nmol/L. The risk of low vitamin D status was several-fold higher among persons of ethnic minority. However, additional data from quality bio-banked sera would be required to improve these estimates. To address the question of dietary requirements for vitamin D among under-researched life-stage and population groups, four dose-response RCTs conducted in Northern Europe showed that vitamin D₃ intakes of 8 and 13 μg/day prevented 25(OH)D decreasing below 30 nmol/L in white children and adolescents and 20 and 30 μg/day, respectively, achieved ≥50 nmol/L. Among white women during pregnancy, 30 μg/day is required to prevent umbilical cord 25(OH)D, representing new-born vitamin D status, below 25 nmol/L. While 8 μg/day protected white women in Finland at the 30 nmol/L cut-off, 18 μg/day was needed by women of East African descent to prevent 25(OH)D decreasing below 30 nmol/L during wintertime. Replicate RCTs are needed in young children <5 years and in school-age children, teens and pregnant women of ethnic minority. Using a series of food production studies, food-based RCTs and dietary modelling experiments, ODIN research shows that diverse fortification strategies could safely increase population intakes and prevent low vitamin D status. Building on this solid technological platform, implementation research is now warranted to scale up interventions in real-world settings to eradicate vitamin D deficiency.

Effect of multiple micronutrient fortified milk consumption on vitamin D status among school-aged children in rural region of Morocco

Vitamin D deficiency is a health problem in both developed and developing countries. The aim of this study was to determine the effect of multi-vitamin fortified milk consumption on vitamin D status among children living in the mountainous region of Morocco. Children aged 7 to 9 years (n = 239; 49% of girls vs 51% of boys) participated in a double-blind longitudinal study, where they were divided in 2 groups: a fortified group that received daily 200 mL of fortified ultra-high-temperature (UHT) milk enriched with 3 μg of vitamin D₃ and a nonfortified group that received 200 mL of nonfortified UHT milk with a natural abundance of vitamin D₃ (about 1.5 μg). Blood samples were collected 3 times (at baseline, then at the fourth and ninth months). The average weight, height, and z score of body mass index for age of participants were 22.8 ± 2.6 kg, 121.5 ± 5.2 cm, and -0.2 ± 0.6 kg/m², respectively. At baseline, 47.5% of children had a concentration of 25-hydroxyvitamin D below 50 nmol/L. At the end of the study the prevalence of vitamin D <50 nmol/L decreased significantly by 37.6% in the fortified group. These results reveal prevalent vitamin D insufficiency (<50 nmol/L) during winter among rural Moroccan school-aged children, which seems to be better improved by consuming the fortified milk instead of the nonfortified one.

Sun behaviour and physical activity associated with autumn vitamin D status in 4–8-year-old Danish children

Objective

To explore determinants of serum 25-hydroxyvitamin D (s-25(OH)D) during autumn in young, Caucasian children not consuming vitamin D-fortified foods or supplements, and explore differences in sun behaviours between pre-school and school children.

Design

In September–October, s-25(OH)D was measured by LC–MS/MS; physical activity, sun behaviours and vitamin D intake were assessed with questionnaires.

Setting

Baseline data from the ODIN Junior trial at 55°N.

Subjects

Children aged 4–8 years (n130), of whom 96% gave blood samples.

Results

Mean s-25(OH)D was 56·8 (sd12·5) nmol/l and positively associated with fat-free mass index (P=0·014). Children being active 6–7 h/week had 5·6 (95% CI 1·1, 10·0) nmol/l higher s-25(OH)D than less active children (P=0·014). Children seeking shade sometimes or rarely/never had 7·0 (95% CI 1·2, 12·9;P=0·018) and 7·2 (95% CI 0·8, 13·6;P=0·028) nmol/l higher s-25(OH)D, respectively, than children always/often seeking shade. Pre-school children had more sun-safe behaviour than school children in terms of use of a hat, sunscreen and sunscreen sun protection factor (P<0·05). In school but not pre-school children, using a hat rarely/never was associated with 12·1 (95% CI 2·5, 21·7;P=0·014) nmol/l higher s-25(OH)Dv. always/often (Pinteraction=0·019). Vitamin D intake was not associated with s-25(OH)D (P=0·241).

Conclusions

Physical activity and sun behaviours are associated with s-25(OH)D in young children. Identifying factors influencing autumn s-25(OH)D is relevant to optimize levels before sun exposure diminishes. Strategies to reduce risk of inadequacy should consider risk of skin cancer and sunburn, and could include fortification and/or vitamin D supplementation.

Vitamin D fortification of foods and prospective health outcomes

Vitamin D is essential for bone health and has significant roles in non-skeletal health and organ function. Dermal synthesis through exposure to ultraviolet B light is the major natural source of vitamin D, while only a small portion of the necessary amount can be acquired by a diet without fortified foods. In recent years, vitamin D deficiency as a result of lifestyles with inadequate sun exposure, has received increased attention due to its association with the increased risk of serious chronic diseases. This review summarizes our current understanding of food fortification strategies with vitamin D and the resulting health impact. Conventional and biotechnological approaches can be used for the production of new and novel vitamin D rich or vitamin D fortified foods. The availability of a wider range of every-day consumed fortified foods as part of a "Daily D" public health policy can contribute to the improvement of vitamin D status and to prevention of vitamin D deficiency.

Effect of Vitamin D Supplementation, Food Fortification, or Bolus Injection on Vitamin D Status in Children Aged 2-18 Years: A Meta-Analysis

Meta-analyses on the effect of vitamin D intake on status in children are lacking, especially those focused on vitamin D-fortified foods. The objective of this meta-analysis was to investigate the effect of vitamin D interventions (fortified foods, supplements, bolus injections) on vitamin D status in children 2-18 y of age. Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, literature searches were conducted up to December 2016. Randomized placebo-controlled vitamin D interventions in healthy children aged 2-18 y were included. A random-effects model was used with I2 assessing heterogeneity. We included 26 trials (5403 children) with interventions (n = 9 fortified foods, n = 15 supplements, n = 2 bolus injections) from 100-4000 IU vitamin D/d over 4 wk to 2 y. The serum 25-hydroxyvitamin D [25(OH)D] weighted mean difference for all 26 trials (23.5 nmol/L; 95% CI: 20.7, 26.3 nmol/L; I2 = 99.9%) resulted in a mean increase of 1.0 nmol/L (95% CI: 0.3, 1.7 nmol/L) for each increase of 100 IU vitamin D/d (per 1 µg/d : 0.4 nmol/L; 95% CI: 0.1, 0.7 nmol/L). The response per 100 IU vitamin D/d was greater in trials with a mean baseline serum 25(OH)D <30 nmol/L, with the use of fortified foods and with baseline vitamin D intakes <100 IU/d. In conclusion, the serum 25(OH)D response to vitamin D intake differs on the basis of baseline status, intakes, and delivery mode, but not age, sex, or latitude.

Vitamin D status and functional health outcomes in children aged 2-8 y: a 6-mo vitamin D randomized controlled trial

Background

Most Canadian children do not meet the recommended dietary intake for vitamin D.

Objectives

The aims were to test how much vitamin D from food is needed to maintain a healthy serum 25-hydroxyvitamin D3 [25(OH)D3] status from fall to spring in young children and to examine musculoskeletal outcomes.

Design

Healthy children aged 2-8 y (n = 51) living in Montreal, Canada, were randomly assigned to 1 of 2 dietary vitamin D groups (control or intervention to reach 400 IU/d by using vitamin D-fortified foods) for 6 mo, starting October 2014. At baseline and at 3 and 6 mo, anthropometric characteristics, vitamin D metabolites (liquid chromatography-tandem mass spectrometry), and bone biomarkers (IDS-iSYS, Immunodiagnositc Systems; Liaison; Diasorin) were measured and physical activity and food intakes surveyed. At baseline and at 6 mo, bone outcomes and body composition (dual-energy X-ray absorptiometry) were measured. Cross-sectional images of distal tibia geometry and muscle density were conducted with the use of peripheral quantitative computed tomography scans at 6 mo.

Results

At baseline, participants were aged 5.2 ± 1.9 (mean ± SD) y and had a body mass index z score of 0.65 ± 0.12; 53% of participants were boys. There were no differences between groups in baseline serum 25(OH)D3 (66.4 ± 13.6 nmol/L) or vitamin D intake (225 ± 74 IU/d). Median (IQR) compliance was 96% (89-99%) for yogurt and 84% (71-97%) for cheese. At 3 mo, serum 25(OH)D3 was higher in the intervention group (P < 0.05) but was not different between groups by 6 mo. Although lean mass accretion was higher in the intervention group (P < 0.05), no differences in muscle density or bone outcomes were observed.

Conclusions

The consumption of 400 IU vitamin D/d from fall to spring did not maintain serum 25(OH)D3 concentration or improve bone outcomes. Further work with lean mass accretion as the primary outcome is needed to confirm if vitamin D enhances lean accretion in healthy young children. This trial was registered at www.clinicaltrials.gov as NCT02387892.

Anticancer potential of dietary vitamin D and ascorbic acid: A review

Cancers have been the leading cause of death worldwide and poor diet and physical inactivity are major risk factors in cancer-related deaths. Micronutrients such as vitamins and minerals appear to have preventive properties against cancer. One important mechanism by which dietary changes can exert preventive effects on cancer is via the modulation of micronutrient concentrations in target tissues. Many of these micronutrients are available in the form of dietary supplements, and the intake of these supplements is prevalent in various parts of the world. However, in most cases, it is not known which micronutrient (or combination of micronutrients) is best when it comes to lowering the risk of cancer. The present review illustrates the effect of vitamin D and ascorbic acid intake on preventing cancer.

Modelling of adequate and safe vitamin D intake in Danish women using different fortification and supplementation scenarios to inform fortification policies

Purpose

Fortification of foods with vitamin D may be a population-based solution to low vitamin D intake. We performed modelling of vitamin D from diet, fortified foods and supplements in a population of Danish women 18–50 years, a risk group of vitamin D deficiency, to inform fortification policies on safe and adequate levels.

Methods

Based on individual habitual dietary vitamin D intake of female participants from the Danish National Survey of Dietary Habits and Physical Activity (DANSDA) (n = 855), we performed graded intake modelling to predict the intake in six scenarios increasing the vitamin D intake from a habitual diet without fish to habitual diet including fish, fortified foods and supplements (40/80 µg). Four different foods were used as potential foods to fortify with vitamin D.

Results

The vitamin D intake was below the Average Requirement (AR) of 7.5 µg/day for 88% of the assessed women. Safe levels of intake (< 100 µg/day) were observed after adding four different fortified foods (plain yoghurt, cheese, eggs and crisp-bread) contributing with a total of 20 µg/day and a vitamin D supplement of 40 µg/day to the habitual diet. Consumption of fish, fortified foods and a vitamin D supplement of 80 µg resulted in intakes above the Tolerable Upper Intake Level (UL) < 100 µg/day.

Conclusions

In a Danish female population with a low vitamin D intake, low-dose fortification of different foods with vitamin D may be an effective and safe population-based approach.

The positive impact of general vitamin D food fortification policy on vitamin D status in a representative adult Finnish population: evidence from an 11-y follow-up based on standardized 25-hydroxyvitamin D data

Background: A systematic vitamin D fortification of fluid milk products and fat spreads was started in 2003 in Finland to improve vitamin D status. Objective: We investigated the effects of the vitamin D fortification policy on vitamin D status in Finland between 2000 and 2011.Design: Serum 25-hydroxyvitamin D [S-25(OH)D] concentrations of a nationally representative sample comprising 6134 and 4051 adults aged ≥30 y from the Health 2000 and Health 2011 surveys, respectively, were standardized according to the Vitamin D Standardization Program with the use of liquid chromatography-tandem mass spectrometry. Linear and logistic regression models were used to assess the change in S-25(OH)D concentrations.Results: Between 2000 and 2011, the mean S-25(OH)D increased from 48 nmol/L (95% CI: 47, 48 nmol/L) to 65 nmol/L (95% CI: 65, 66 nmol/L) (P < 0.001). The prevalence of vitamin D supplement users increased from 11% to 41% (P < 0.001). When analyzing the effect of fortification of fluid milk products, we focused on supplement nonusers. The mean increase in S-25(OH)D in daily fluid milk consumers (n = 1017) among supplement nonusers was 20 nmol/L (95% CI: 19, 21 nmol/L), which was 6 nmol/L higher than nonconsumers (n = 229) (14 nmol/L; 95% CI: 12, 16 nmol/L) (P < 0.001). In total, 91% of nonusers who consumed fluid milk products, fat spreads, and fish based on Finnish nutrition recommendations reached S-25(OH)D concentrations >50 nmol/L in 2011.Conclusions: The vitamin D status of the Finnish adult population has improved considerably during the time period studied. The increase is mainly explained by food fortification, especially of fluid milk products, and augmented vitamin D supplement use. Other factors, such as the difference in the ultraviolet radiation index between 2000 and 2011, may partly explain the results. When consuming vitamin D sources based on the nutritional recommendations, vitamin D status is sufficient [S-25(OH)D ≥50 nmol/L], and supplementation is generally not needed.

Common genetic variants are associated with lower serum 25-hydroxyvitamin D concentrations across the year among children at northern latitudes

In a longitudinal study including 642 healthy 8–11-year-old Danish children, we investigated associations between vitamin D dependent SNP and serum 25-hydroxyvitamin D (25(OH)D) concentrations across a school year (August–June). Serum 25(OH)D was measured three times for every child, which approximated measurements in three seasons (autumn, winter, spring). Dietary and supplement intake, physical activity, BMI and parathyroid hormone were likewise measured at each time point. In all, eleven SNP in four vitamin D-related genes: Cytochrome P450 subfamily IIR1 (CYP2R1); 7-dehydrocholesterol reductase/nicotinamide adenine dinucleotide synthetase-1(DHCR7/NADSYN1); group-specific complement (GC); and vitamin D receptor were genotyped. We found minor alleles of CYP2R1 rs10500804, and of GC rs4588 and rs7041 to be associated with lower serum 25(OH)D concentrations across the three seasons (all P<0·01), with estimated 25(OH)D differences of −5·8 to −10·6 nmol/l from major to minor alleles homozygosity. In contrast, minor alleles homozygosity of rs10741657 and rs1562902 in CYP2R1 was associated with higher serum 25(OH)D concentrations compared with major alleles homozygosity (all P<0·001). Interestingly, the association between season and serum 25(OH)D concentrations was modified by GC rs7041 (Pinteraction=0·044), observed as absence of increase in serum 25(OH)D from winter to spring among children with minor alleles homozygous genotypes compared with the two other genotypes of rs7041 (P<0·001). Our results suggest that common genetic variants are associated with lower serum 25(OH)D concentrations across a school year. Potentially due to modified serum 25(OH)D response to UVB sunlight exposure. Further confirmation and paediatric studies investigating vitamin D-related health outcomes of these genotypic differences are needed.

A micronutrient-fortified young-child formula improves the iron and vitamin D status of healthy young European children: a randomized, double-blind controlled trial

BACKGROUND

Iron deficiency (ID) and vitamin D deficiency (VDD) are common among young European children because of low dietary intakes and low compliance to vitamin D supplementation policies. Milk is a common drink for young European children. Studies evaluating the effect of milk fortification on iron and vitamin D status in these children are scarce.

OBJECTIVE

We aimed to investigate the effect of a micronutrient-fortified young-child formula (YCF) on the iron and vitamin D status of young European children.

DESIGN

In this randomized, double-blind controlled trial, healthy German, Dutch, and English children aged 1-3 y were allocated to receive either YCF (1.2 mg Fe/100 mL; 1.7 μg vitamin D/100 mL) or nonfortified cow milk (CM) (0.02 mg Fe/100 mL; no vitamin D) for 20 wk. Blood samples were taken before and after the intervention. The primary and secondary outcomes were change from baseline in serum ferritin (SF) and 25-hydroxyvitamin D [25(OH)D], respectively. ID was defined as SF <12 μg/L in the absence of infection (high-sensitivity C-reactive protein <10 mg/L) and VDD as 25(OH)D <50 nmol/L. Statistical adjustments were made in intention-to-treat analyses for sex, country, age, baseline micronutrient status, and micronutrient intake from food and supplements (and sun exposure in the case of vitamin D outcomes).

RESULTS

The study sample consisted of 318 predominantly Caucasian (∼95%) children. The difference in the SF and 25(OH)D change between the treatment groups was 6.6 μg/L (95% CI: 1.4, 11.7 μg/L; P = 0.013) and 16.4 nmol/L (95% CI: 9.5, 21.4 nmol/L; P < 0.001), respectively. The probability of ID (OR 0.42; 95% CI:0.18, 0.95; P = 0.036) and VDD (OR 0.22; 95% CI: 0.01, 0.51; P < 0.001) after the intervention was lower in the YCF group than in the CM group.

CONCLUSION

Micronutrient-fortified YCF use for 20 wk preserves iron status and improves vitamin D status in healthy young children in Western Europe. This trial was registered at www.trialregister.nl as NTR3609.

Dietary strategies for achieving adequate vitamin D and iron intakes in young children in Ireland

BACKGROUND

Inadequate intakes of vitamin D and iron have been reported in young children in Ireland. The present study aimed to identify the main foods determining vitamin D and iron intakes and to model the impact of dietary strategies to improve adequacy of these micronutrients in young children.

METHODS

The present study is based on the Irish National Pre-School Nutrition Survey (NPNS), which estimated food and nutrient intakes in a representative sample (n = 500) of children (aged 1-4 years) using a 4-day weighed food record. Dietary strategies were modelled using DaDiet^© software (Dazult Ltd, Co. Kildare, Republic of Ireland) and the usual intake distribution, prevalence of inadequate intakes and risk of excessive intakes were estimated using the National Cancer Institute method.

RESULTS

Fortified foods and nutritional supplements were the key foods influencing the intakes of vitamin D and iron. Adding a 5 μg day^-1 vitamin D supplement, fortifying cow's milk (CM) with vitamin D or replacing CM with growing-up milk (GUM) would modestly increase intakes of vitamin D. A combined strategy of fortifying CM with vitamin D or replacing CM with GUM plus a 5 μg day^-1 vitamin D supplement would increase mean intakes of vitamin D (from 3.5 μg day^-1 at baseline to ≥11 μg day^-1 ) and substantially reduce the prevalence of inadequate intakes (from >95% to 12-36%). Fortifying CM with iron or replacing CM with GUM would increase mean intakes of iron (from 7.3 mg day^-1 to >10 mg day^-1 ), achieving adequate intakes across all ages.

CONCLUSIONS

Based on real food consumption data in a representative sample of Irish children, we have shown that through targeted dietary strategies adequate intakes of iron are achievable and intakes of vitamin D could be greatly improved.

Food-based solutions for vitamin D deficiency: putting policy into practice and the key role for research

Recent re-evaluations of dietary reference values (DRV) for vitamin D have established intake requirements between 10 and 20 µg/d. National nutrition surveys indicate that habitual mean intakes of vitamin D in the population are typically in the range 3-7 µg/d. As vitamin D supplementation will not be effective at a population level because the uptake is generally low, creative food-based solutions are needed to bridge the gap between current intakes and these new requirement values. The overarching aim of this review is to highlight how food-based solutions can have an important role in bridging this gap and counteracting vitamin D inadequacy in Europe and elsewhere. The present review initially briefly overviews very recent new European DRV for vitamin D and, while not in agreement on requirement estimates, how they point very clearly to the need for food-based solutions. The review discusses the need for traditional fortification of foods in the dairy and other sectors, and finally overviews recent advances in the area of biofortification of food with vitamin D. In conclusion, increasing vitamin D intakes across the population distribution is important from a public health perspective to reduce the high degree of inadequacy of vitamin D intake in Europe. Fortification, including biofortification, of a wider range of foods, which accommodate diversity, is likely to have the potential to increase vitamin D intakes across the population distribution. Research has had, and will continue to have, a key role in terms of developing food-based solutions and tackling vitamin D deficiency.

Reaching Nutritional Adequacy Does Not Necessarily Increase Exposure to Food Contaminants: Evidence from a Whole-Diet Modeling Approach

BACKGROUND

Dietary guidelines are designed to help meet nutritional requirements, but they do not explicitly or quantitatively account for food contaminant exposures.

OBJECTIVE

In this study, we aimed to test whether dietary changes needed to achieve nutritional adequacy were compatible with acceptable exposure to food contaminants.

METHODS

Data from the French national dietary survey were linked with food contaminant data from the French Total Diet Study to estimate the mean intake of 204 representative food items and mean exposure to 27 contaminants, including pesticides, heavy metals, mycotoxins, nondioxin-like polychlorinated biphenyls (NDL-PCBs) and dioxin-like compounds. For each sex, 2 modeled diets that departed the least from the observed diet were designed: 1) a diet respecting only nutritional recommendations (NUT model), and 2) a diet that met nutritional recommendations without exceeding Toxicological Reference Values (TRVs) and observed contaminant exposures (NUTOX model). Food, nutrient, and contaminant contents in observed diets and NUT and NUTOX diets were compared with the use of paired t tests.

RESULTS

Mean observed diets did not meet all nutritional recommendations, but no contaminant was over 48% of its TRV. Achieving all the nutrient recommendations through the NUT model mainly required increases in fruit, vegetable, and fish intake and decreases in meat, cheese, and animal fat intake. These changes were associated with significantly increased dietary exposure to some contaminants, but without exceeding 57% of TRVs. The highest increases were found for NDL-PCBs (from 26% to 57% of TRV for women). Reaching nutritional adequacy without exceeding observed contaminant exposure (NUTOX model) was possible but required further departure from observed food quantities.

CONCLUSIONS

Based on a broad range of nutrients and contaminants, this first assessment of compatibility between nutritional adequacy and toxicological exposure showed that reaching nutritional adequacy might increase exposure to food contaminants, but within tolerable levels. However, there are some food combinations that can meet nutritional recommendations without exceeding observed exposures.

Prevalence and determinants of vitamin D deficiency in healthy French adults: the VARIETE study

The U.S. Institute of Medicine considers that a serum 25-hydroxyvitamin D (25OHD) concentration >20 ng/mL corresponds to optimal vitamin D status in the general population. Old studies of vitamin D status in the French general population have demonstrated high prevalence of insufficiency. We measured serum 25OHD, 1,25(OH)2D, PTH, calcium, phosphorus, and creatinine levels in 892 French Caucasian healthy subjects (463 men, 429 women) aged from 18 to 89 years. The 25OHD concentration was similar in men (24.1 ± 8.2 ng/mL) and women (23.4 ± 8.0 ng/mL). 25OHD concentrations of <10, <12, <20, and <30 ng/mL were found in respectively 6.3, 9.9, 34.6, and 80.3 % of subjects. Residence in northern France (odds ratio [OR] 1.91), blood sampling between January and March (OR 7.74), BMI ≥24 kg/m(2) (OR 1.81), and age 60 years or more (OR 1.99) were significant determinants of hypovitaminosis D (25OHD <20 ng/mL). The serum 25OHD level correlated positively with 1,25(OH)2D and negatively with PTH. 25OHD values below 20 ng/mL were associated with lower 1,25(OH)2D levels, and 25OHD values below 27 ng/mL were associated with higher PTH levels. Many French healthy adults have a 25OHD concentration <20 ng/mL, especially during winter months. Actions to improve the vitamin D status of the French general population are urgently needed.

Standardizing serum 25-hydroxyvitamin D data from four Nordic population samples using the Vitamin D Standardization Program protocols: Shedding new light on vitamin D status in Nordic individuals

Knowledge about the distributions of serum 25-hydroxyvitamin D (25(OH)D) concentrations in representative population samples is critical for the quantification of vitamin D deficiency as well as for setting dietary reference values and food-based strategies for its prevention. Such data for the European Union are of variable quality making it difficult to estimate the prevalence of vitamin D deficiency across member states. As a consequence of the widespread, method-related differences in measurements of serum 25(OH)D concentrations, the Vitamin D Standardization Program (VDSP) developed protocols for standardizing existing serum 25(OH)D data from national surveys around the world. The objective of the present work was to apply the VDSP protocols to existing serum 25(OH)D data from a Danish, a Norwegian, and a Finnish population-based health survey and from a Danish randomized controlled trial. A specifically-selected subset (n 100-150) of bio-banked serum samples from each of the studies were reanalyzed for 25(OH)D by LC-MS/MS and a calibration equation developed between old and new 25(OH)D data, and this equation was applied to the entire data-sets from each study. Compared to estimates based on the original serum 25(OH)D data, the percentage vitamin D deficiency (< 30 nmol/L) decreased by 21.5% in the Danish health survey but by only 1.4% in the Norwegian health survey; but was relatively unchanged (0% and 0.2%) in the Finish survey or Danish RCT, respectively, following VDSP standardization. In conclusion, standardization of serum 25(OH)D concentrations is absolutely necessary in order to compare serum 25(OH)D concentrations across different study populations, which is needed to quantify and prevent vitamin D deficiency.